>> sure, the d-day d-day you're mentioning, chairwoman miller, are the two sons sector. in looking at fiscal year 2062 mike 2011 the apprehension rate remained relatively the same. the apprehension rate than the others southwest border sectors. over time. they provided the tucson sector rate as an example in the report because of the high traffic sector. in terms of what that means, the retention rate is looking at the to illegal entrants who are apprehended, arrested by border patrol and their ability to make arrests can be impacted by various factors including the agent are deployed to know what the terrain is like. so some of those factors six lane for differences in the rates across sectors. >> i appreciate that. chief, talking about the apprehension rate, you mentioned maybe it's not the best way, but certainly one way we measure border security. perhaps we should do something other than apprehensions is a better way of assuring border security. i'd also like you to expand on your goal. you talked about 90% what does a secure border look like? a 90% effective rate w